Bi-phasic O3/P2 sodium layered oxides have emerged as leading candidates for the commercialisation of next-generation sodium-ion batteries. However, beyond simply altering the sodium content, rational control of the O3/P2 ratio in these materials has proven particularly challenging despite being crucial for the realization of high-performance electrode materials. Here, using abundant elements, we manipulate the O3/P2 ratio using the average ionic radius of the transition metal layer and different synthesis conditions. These methods allow deterministic control over the O3/P2 ratio, even for constant Na contents. In addition, tuning the O3/P2 ratio yields high-performing materials with different performance characteristics, with a P2-rich material achieving high rate capabilities and excellent cycling stability (92% retention, 50 cycles), while an O3-rich material displayed an energy density up to 430 Wh kg⁻¹, (85%, 50 cycles). These insights will help guide the rational design of future high-performance materials for sodium-ion batteries.

双相 O3/P2 钠层状氧化物已成为下一代钠离子电池商业化的主要候选材料。然而，除了简单地改变钠含量之外，合理控制这些材料中的 O3/P2 比率已被证明特别具有挑战性，尽管这对于实现高性能电极材料至关重要。在这里，我们使用丰富的元素，使用过渡金属层的平均离子半径和不同的合成条件来控制 O3/P2 比率。这些方法允许对 O3/P2 比率进行确定性控制，即使对于恒定的 Na 含量也是如此。此外，调整 O3/P2 比率可产生具有不同性能特征的高性能材料，富含 P2 的材料可实现高倍率性能和出色的循环稳定性（92% 保留，50 个循环），^-1，（85%，50 个循环）。这些见解将有助于指导未来高性能钠离子电池材料的合理设计。